session 5 & 6 - toc tools and app

Session 5/8,TOC Tools & Applications

M. Karthik,Lean Manufacturing [email protected]

Topics

TOC Tools Current Reality Tree Future Reality Tree Transition Tree Prerequisite Tree Evaporating Cloud

TOC Applications

TOC Advantages and Disadvantages

Thinking Processes

Set of tools to help managers walk through the steps of initiating and implementing TOC.

The Thinking Processes comprise

a suite of five logic diagrams (four trees and a "cloud”)

a set of logic rules.

Value of Thinking Process

The value of the Thinking Process lies in its capability to start with an vague problem

Then work methodically through to a clearly defined series of prescriptive steps for overcoming the problem.

Types of T.P

The 5 diagrams use two different types of logic rules.

Cause and Effect Current Reality Tree Future Reality Tree Transition Tree

Necessary Condition Prerequisite Tree Evaporating Cloud

Cause and Effect

Cause and Effect thinking is built up on “sufficient cause”

Sufficiency Cause Types: "A is sufficient to cause C” "If both A and B occur together, then they will be

sufficient to cause C” "A and B (separately) both contribute to C, and between

them are sufficient to cause C".

Necessary Condition

"In order to achieve A we must have B".

Thinking Processes of TOC

An Integrated Thinking Process using Logical Tools

CRT enables management to start with observable Undesirable Effects (UDE) in the system’s performance.

Then work backward through an unbroken chain of cause-and-effect to the ROOT CAUSE of these visible problems.

Then, the Evaporating Cloud Diagram helps define possible conflicts that might arise in CHANGING the root cause


EC diagram also helps to develop creative ways to resolve conflicts.

The solutions generated with the Evaporating Cloud are TESTED with a FUTURE REALITY TREE for their effectiveness at relieving the UDE’s identified.


If the solution proves to be valid, the Prerequisite Tree can help identify and overcome implementation obstacles in the order that they must be addressed for quick, effective execution.

Then, the structure of the Prerequisite Tree can be converted into a series of step-by-step actions for achieving the objective.

Breaking Down the diagrams

Cause and Effect

It means –

“If cause – then effect. ”


Symptom

If we start with the observed effect; its symptom.


Underlying Cause of Symptom

Might be 2 underlying causes for a symptom.


Common Cause

At time more symptoms arise from one common cause.


Additional Cause

Current Reality Tree (CRT)

A current reality tree is a statement of an underlying core problem and the symptoms that arise from it.

It maps out a sequence of cause and effect from the core problem to the symptoms.

Most of the symptoms will arise from the one core problem or a core conflict.

Remove the core problem and we may well be able to remove each of the symptoms as well.

Operationally we work backwards from the apparent undesirable effects or symptoms to uncover or discover the underlying core cause.


Underneath the cause of a problem, the real cause is hidden.

In every case, we must dig up the real cause by asking why, why, why, why, why. (5 Why’s)

In this tree several symptoms are mapped back to other common problems and in-turn a single core problem.

Note too, that there is also a neutral effect.

The neutral effect, while of its self is not negative, it is needed to sufficiently describe the current reality.


Some people prefer to call the symptoms undesirable effects or UDE.

How do we read such a tree?

From the bottom to the top.

If cause then effect.

And where there is an ellipse indicating a logical; we use if cause and if other cause then effect.

Current Reality Tree (CRT) Example


Feedback is an absolutely essential part of any organization. This is represented by the arrow from UDE to problem.


Core Problem/ Core Conflict:

In business situations, however, it is quite possible that we will not be aware of the core problem in the first instance, and instead we will arrive at a core conflict.


If we are aware of a core problem and it is within our sphere of control or even influence, then we will try to do something about it.

However, consider the case of a core conflict.

Even when we are in total control of the situation we may let the conflict continue to exist because both of the entities Neutral Effect A and Neutral Effect B are required in order to satisfy something else.

The entities that give rise to all the problems are not perceived to be a problem by themselves.

Evaporating Cloud (EC)/ Conflict Resolution Diagram (CRD)

A cloud is an elegant graphical means of displaying and solving an apparent conflict or dilemma between two actions.

It is also sometimes known as a conflict resolution diagram; however, its correct name is a cloud.

Central to the use of clouds as a problem solving device is the assumption that there are no conflicts in nature only false assumptions.

"There must be a false assumption that we make about reality that causes a conflict to exist."

Let's look at this from another perspective and another culture Japan; "Problems exist because people believe they exist. If there were no

people there would be no problems. People are also the ones who decide that a problem has been solved. Problem solving is the most typical human behavior.”


The apparent conflicts that do arise and which we do want to solve are likely to be of two types; (1) Opposite conditions: conditions that are mutually exclusive. (2) Different alternatives: conditions that preclude one another.

We might use a cloud for everyday free-standing conflicts or dilemmas, or as a tool to resolve the core problem or core conflict made apparent as a result of the construction of a current reality tree.

The key point, however, is that you must want to solve your problem or dilemma. Without the will to solve the problem, the way to do it won't be apparent at all.


Countermeasures And Injections:

Countermeasures are used to mitigate a currently undesirable effect by removal or replacement with something else.

An injection is any new idea that we introduce into our current reality to produce a new and desirable outcome.

Injections go one step further they may in fact create a totally new and desirable step as well as mitigating the currently undesirable effect.

Breaking the cloud by developing an injection builds understanding and agreement on the direction of the solution to the problem at hand.


A cloud is built out of 5 entities.

The first is a common objective which we want to satisfy.

In order to satisfy the common objective it is necessary that we fulfill two needs.

In order to satisfy the needs it is necessary that we fulfill the two wants.

However, the two wants are in conflict with each other as indicated by the arrows


Some people like to use the terms requirement and pre-requisite. It makes no difference.

This shows us the shape of a cloud but it doesn’t teach us how to make one or how to break one.

The whole point of making a cloud is to break it; to break the conflict with a no-compromise win/win solution.

Evaporating Cloud (EC)/ Conflict Resolution Diagram (CRD) Example.

So let's do this by using a real example that is familiar to most people.

Have you ever had the conflict ask for a wage-salary rise/don’t ask for a wage-salary rise?

I’m sure there most people have.


Now, we need to ask ourselves, what are the needs that we are trying to address?

Let’s assume for instance that the need for wanting to ask for a salary rise is our happiness.

And the need for not wanting to ask for a salary rise is our boss’s happiness.


That just leaves us with the objective to complete.

In these types of cases something general will usually do.

The theme seems to be happiness, so let's make the objective maintain happiness.


So now we have constructed a cloud from scratch, let’s learn how to read this diagram.

Side 1: In order to maintain happiness it is necessary to keep the boss's happiness. And in order to keep the boss's happiness it is necessary to not ask for a salary rise.

Side 2: In order to maintain happiness it is necessary to keep my happiness. And in order to keep my happiness it is necessary to ask for a salary rise.

Finally, we come to the conflict, the crux of the matter.

However, not asking for a salary rise and asking for a salary rise are in direct conflict with one another.

What are we going to do about the conflict?


Well, Goldratt argues that there are no conflicts in nature and therefore in business there can be no conflicts only erroneous assumptions.

Therefore, we need to search out the assumptions upon which our conflict is based.

Where are the assumptions in the cloud? They are under each of

the arrows.


And now, let’s add some real assumptions to the needs/wants arrow.


Now we must ask how many of these assumptions are valid, how many are invalid, and can we overcome any of the remaining valid assumptions with a new idea or reality. We will call this new idea or reality an injection.

Let's assume that it is true that the company has no money;

Let’s assume the boss will resent our asking, the boss will be in a difficult position of turning our request down even if he wants to action it.

So the assumptions on the top side are valid and must remain.


Let's look along the bottom.

Our living expenses are rising. Are they really? Maybe, if we were more honest with ourselves, we should have said that our discretionary expenses are rising. Let's keep going.

Our pay parity is decreasing. [Ah this looks like a real problem.]

There is someone else in the company who is younger or less experienced who is on the same or greater salary.

If that is the case then it is quite likely that we feel our expenses are rising because we want to justify our increase in pay parity.

A possible injection then becomes Increase our non-pay parity.


Let's clean the diagram up, so that we can see that the conflict has been broken.


So the cloud lets us identify a way to satisfy both needs and the common objective without a conflict, and with a win/win injection.

End Of Session 5.

Future Reality Tree (FRT)

A future reality tree allows us to map out our future expectations given that we will introduce something new into our reality the injection that we developed to break our current reality problem or core conflict.

A future reality tree lets us test the future outcome using known cause and effect to check that what we want is what we will get.

At its simplest, a future reality tree might be thought of as a current reality with all the undesirable effects (UDE's) changed to desirable effects (DE's).

Future Reality Tree (FRT)

The presence of the new idea or ideas as injections will change reality from undesirable outcomes of the present to desirable outcomes of the future.

Maybe we need several different injections to achieve this.

The future reality tree is the tool of choice in gaining understanding and agreement that the solution we have decided upon will account for all of the undesirable effects that we currently experience and built into our current reality tree.

How to build a Future Reality

Tree ?

How can we construct a future reality tree from a current reality tree with a core conflict, and a cloud?

Let's return to our current reality tree and core conflict first and see if we can see the relationship there with the cloud.


Tree ?

Do you see the wants of the cloud coming from the two neutral entities of the current reality tree?

Now we can see why we felt we must have the two entities and why we felt they couldn't be negative effects.

They are the wants that arise from two different needs that satisfy a common objective.


Tree ?

Once we have the injection usually we would work through the cloud separately step by step, then the future reality tree can unfold.

In fact in this example we have two injections, one, the main one, arising from the cloud, and a second, minor one which we need to tweak the solution to ensure all the undesirable effects become desirable outcomes.

Example of Future Reality Tree ?

http://www.intelligentmanagement.ws/learningcentre/what-are-the-thinking-process-tools/real-life-example-of-a-future-reality-tree-the-proprint-case-study/

Prerequisite Tree

The pre-requisite tree ought to be considered the most important tree in the Thinking Process suite.

It is the tree that allows us to overcome the obstacles that stop us from implementing our plan.

It is also the tree that in fact becomes the implementation plan.

And it is the tree to which timelines, responsibilities, and accountabilities can be assigned to.

The pre-requisite tree occupies the position of plan amongst the Thinking Process tools. Skim it at your peril.

“you can plan to fail, or you can fail to plan”

Prerequisite Tree

The pre-requisite tree is composed of two elements, an obstacle an intermediate objective.

The intermediate objective is the action that we must undertake to overcome the obstacle.

There might be several independent obstacles to an injection as in the example below (A and C), or several dependent obstacles in a chain (A and B).

The obstacles are either things that exist now, which we must remove or overcome, or things that don't exist now which we must obtain.


Prerequisite Tree

How do we read a pre-requisite tree?

Like this, from top to bottom;

In order to achieve the injection we must fulfill the intermediate objective in order to overcome the obstacle.


How to build a Prerequisite Tree ?

Firstly we need to choose the injection to address and then solicit; all the obstacles, and all the intermediate objectives that will overcome the obstacles.

So our first step will look like this.


Prerequisite Tree

Second step is to sequence these pairs.


Prerequisite Tree

Second step is to sequence these pairs.

And therefore we have our completed tree.

There may be some steps for which there are no obstacles, but it is useful to add the step for clarity (we must have it), if so add it as an intermediate objective by itself.


Prerequisite Tree

In fact we really only need to know about the intermediate objectives

After all they are the sequence of things that we are now going to do in order to action our injection and make our future reality tree implementable.

A short-hand way of showing a pre-requisite tree as intermediate objectives alone is called an intermediate objective map or an IO map for short.


Prerequisite Tree

Let’s put it all together.

Let's add the IO Map to our future reality tree.

We can slot this short IO map into out future reality tree example like a piece of a jigsaw and see at a glance what the effect will be of completing each of the intermediate objectives and thus the injection.

Here is the full picture.

Transition Tree

This last tool further supports the need to describe HOW TO MAKE THE CHANGE HAPPEN.

Sometimes a plan is developed by a group for other people to use.

Sometimes getting from one IO in a PRT to another requires a finer level of detail in terms of action and results.

It's really a communication and empowerment tool, allowing the recipient of it to follow a path of action with clear understanding of what to expect along the way and why to expect it.

Transition Tree

It is a simple repetitive sufficiency logic construct that puts the actions/tasks in context with the objectives.

Based on simple, "if-then" links, the Transition Tree includes the need for action, the action, the rationale for the action, that desired, expected result, and then reason for the next need in a graphical format

The transition tree includes all the info you need to build a detailed action plan, assess its ability to deliver results, and includes those results to allow development of alternative actions...a real "results-oriented" task list that encourages "empowerment" to offer new solutions.

It sure beats a simple "Do this, then do that, then..." list of tasks that we usually get for instructions.

Transition TreeThe original four elements of the Transition Tree as:1) A condition of existing reality,2) an unfulfilled need,3) a specific action to be taken, and,4) an expected effect of the integration of the preceding three.

Each succeeding level of the Tree is built upon the previous level, with the expected effect taking the place of the unfulfilled need. These build progressively upward to an overall objective or desired effect.

The fifth element added to the Transition Tree is:5) the rationale for a need at the next higher level of the tree.

Transition Tree

Transition Tree has nine basic purposes, these are:

Provide a step by step method for action implementationEnable effective navigation through a change processDetect deviation in progress toward a limited objectiveAdapt or redirect effort, should plans changeCommunicate the reasons for action to othersExecute the injections developed in the EC or FRTAttain the intermediate objectives identified in a PRTDevelop tactical action plans for conceptual or strategic plansPreclude undesirable effects from arising out of implementation

Applications Of TOC

Finance & Accounting

Project management

Marketing and sales

And most importantly LIFE!

Advantages Of TOC

Potential for tremendous increases in productivity with minimal changes to operations.

Most powerful and cost effective tool for increasing production capacity.

Very simple to communicate and apply, making it ideal for shop floor teams.

Great for fostering teamwork as different areas become aware of the constraint and the need to work together to assist the constraint process.

It provides immediate and very tangible benefits.

Allows growth of turnover/productivity without the need for additional space or staff.

Provides a means to evaluate the true value of changes (using T, O, I), and utilize this to select the best options, and drive the right behavior/decisions.

Drawbacks Of TOC

The considerable length of training time required to achieve mastery of the theory.

The need for the cooperation and enthusiasm of all the people involved with the problem, and its over reliance on group work.

Lack of academic scrutiny.

No mathematics to help size the buffers.

Why have a time – buffer ? A normal queue acts as a buffer.

Doesn’t work well with closed constraints.

Topics

TOC Tools Current Reality Tree Future Reality Tree Transition Tree Prerequisite Tree Evaporating Cloud

TOC Applications

TOC Advantages and Disadvantages

session 5 & 6 - toc tools and app

Documents

effect cause

diagrams cause

cause of symptom

root cause

sequence of cause

diagrams common cause

diagrams additional

effect thinking